package org.example;

import java.io.File;

public class Foo {
    public static void main(String[] args) {

        


        StringBuffer a = new StringBuffer("A");
        StringBuffer b = new StringBuffer("B");
        oper(a,b);
        System.out.println(b);
        System.out.println(a+","+b);


    }
    public static void oper(StringBuffer x,StringBuffer y){
        x.append(y);
        System.out.println(x);
        y=x;
        System.out.println(y);
    }
}
